detection of Poisonous Compounds. 331 



bad in Scinde, in 1843, in which the medical officer called on 

 to take up the case was unable to procure either the simplest 

 kinds of apparatus or the most ordinary tests. The other 

 was a case of suspected poisoning which occurred at Ahmeda- 

 bad ; from which station the suspected substances were dis- 

 patched by dak to Bombay : the bottles were broken en route, 

 the substances lost, and the case in consequence dismissed. 

 Not unfrequently also, from inattention to certain precautions 

 for placing the identity of a substance proved to contain 

 poison beyond all doubt, the chain of legal evidence becomes 

 broken, and it then requires but little ingenuity on the part 

 of counsel to make a case break down in consequence. 



In the hope of obviating such circumstances as the above, 

 I have pointed out the following methods of simplifying the 

 processes for the detection of the poisonous compounds of 

 arsenic, mercury, and antimony : those of the two first under 

 the form of white arsenic, orpiment, and realgar, and of 

 corrosive sublimate being by far the most common, indeed 

 almost the only, mineral poisons employed in this part of 

 India.* In the course of my experiments I have succeeded 

 in obtaining evidence of the existence of these poisons in 

 organic mixtures by means so simple, as to require no other 

 apparatus than the test tube, and to demand the least possi- 

 ble degree of skill on the part of the operator. 



The possibility of withdrawing metals from their combina- 

 tions by substitution , is now in constant application in chemi- 

 cal processes, but its superior advantages in the separation 

 of the metallic base of a mineral poison for medico-legal 

 purposes, was first pointed out by the German Chemist 

 Reinsch,t whose method of separating arsenic from its solu- 

 tions, in obedience to this principle, has been found to surpass 

 every other in the three most essential points of an analytic 



* The Bombay Presidency. 

 t Journal fur Praktischen Chemic, 1842, xxiv. 242. 



